Visceral obesity and metabolic syndrome

Effect of long-term whole body vibration training on visceral adipose tissue: a preliminary report

AIM

To determine the effect of whole body vibration (WBV), combined with caloric restriction, on weight, body composition and metabolic risk factors in overweight and obese adults.

METHODS

A randomized, controlled study with a 6-month intervention period and a 6-month 'no intervention' follow-up. 61 of the 79 participants completed the study. Data were collected at baseline and at 3, 6 and 12 months in the control group (CONTROL), the diet only group (DIET), the diet plus fitness group (FITNESS) and the diet plus WBV group (VIBRATION).

RESULTS

Weight decreased significantly in all three intervention groups. Only FITNESS and VIBRATION managed to maintain a weight loss of 5% or more in the long term. Visceral adipose tissue (VAT) changed most in VIBRATION: -47.8 +/- 41.2 and -47.7 +/- 45.7 cm2 after 6 and 12 months respectively compared to CONTROL (-3.6 +/- 20.5 or +26.3 +/- 30.6 cm(2)), DIET (-24.3 +/- 29.8 or -7.5 +/- 28.3 cm(2)) and FITNESS (-17.6 +/- 36.6 or -1.6 +/- 33.3 cm(2)) (p < 0.001).

CONCLUSIONS

Combining aerobic exercise or WBV training with caloric restriction can help to achieve a sustained long-term weight loss of 5-10%. These preliminary data show that WBV training may have the potential to reduce VAT more than aerobic exercise in obese adults, possibly making it a meaningful addition to future weight loss programs.

Are men shortchanged on health? Perspective on health care utilization and health risk behavior in men and women in the United States

BACKGROUND

Significant gender disparities exist in life expectancy and major disease morbidity. There is a need to understand the major issues related to men's health that contributes to these significant disparities. It is hypothesized that, high-risk behaviors and low utilization of all and preventive health services contribute to the higher mortality and the higher and earlier morbidity in men.

METHODS

Data was collected from CDC: Health United States, 2007; Health Behavior of Adults: United States 2002-04; and National Ambulatory Medical Care Survey: 2005 Summary.

RESULTS

In United States, men are more likely to be regular and heavy alcohol drinkers, heavier smokers who are less likely to quit, non-medical illicit drug users, and are more overweight compared to women. Men are less likely to utilize health care visits to doctor's offices, emergency departments (ED), and physician home visits than women. They are also less likely to make preventive care, hospice care, dental care visits, and have fewer hospital discharges and shorter hospital stays than women.

CONCLUSIONS

High-risk behaviors and low utilization of health services may contribute to the lower life expectancy in men. In the context of public health, behavioral and preventive interventions are needed to reduce the gender disparity.

Separate and overlapping metabolic functions of LXRalpha and LXRbeta in C57Bl/6 female mice

The two liver X receptors (LXRs), LXRalpha and LXRbeta, are transcriptional regulators of cholesterol, lipid, and glucose metabolism and are both activated by oxysterols. Impaired metabolism is linked with obesity, insulin resistance, and type 2-diabetes (T2D). In the present study, we aimed to delineate the specific roles of LXRalpha and -beta in metabolic processes. C57Bl/6 female mice were fed a normal or a high-fat diet (HFD) and metabolic responses in wild-type, LXRalpha(-/-), LXRbeta(-/-), and LXRalphabeta(-/-) mice were analyzed. Whole body fat and intramyocellular lipid contents were measured by nuclear magnetic resonance. Energy expenditure was measured in individual metabolic cages. Glucose, insulin, and pyruvate tolerance tests were performed and gene expression profiles analyzed by qPCR. We found that both LXRbeta(-/-) and LXRalphabeta(-/-) mice are resistant to HFD-induced obesity independently of the presence of high cholesterol. Using tolerance tests, we found that, on an HFD, LXRbeta(-/-) mice enhanced their endogenous glucose production and became highly insulin resistant, whereas LXRalpha(-/-) and LXRalphabeta(-/-) mice remained glucose tolerant and insulin sensitive. Gene expression profiling confirmed that LXRbeta is the regulator of lipogenic genes in visceral white adipose tissue (WAT) and muscle tissue and, surprisingly, that Ucp1 and Dio2 are not responsible for the protection against diet-induced obesity observed in LXRbeta(-/-) and LXRalphabeta(-/-) mice. LXRalpha is required for the control of cholesterol metabolism in the liver, while LXRbeta appears to be a major regulator of glucose homeostasis and energy utilization and of fat storage in muscle and WAT. We conclude that selective LXRbeta agonists would be novel pharmaceuticals in the treatment of T2D.

Atorvastatin improves insulin sensitivity in mice with obesity induced by monosodium glutamate

AIM

To examine the mechanisms underlying the effects of atorvastatin on glucose and lipid metabolism.

METHODS

Mice with insulin resistance and obesity induced by monosodium glutamate (MSG) were used. Atorvastatin (80 mg.kg(-1).d(-1)) or vehicle control treatment was given orally once a day for 30 days. Plasma levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and free fatty acids were monitored. Serum insulin and glucose concentrations were used to calculate the insulin resistance index and insulin sensitivity index using a homeostasis model. Body length, waistline circumference, intraperitoneal adipose tissue mass, and total body mass were measured. Semi-quantitative RT-PCR and Western analysis were used to determine the expression of inflammatory factors and proteins involved in inflammation signaling pathways.

RESULTS

Atorvastatin improved insulin sensitivity, ameliorated glucose tolerance, and decreased plasma levels of total cholesterol, triglycerides, LDL-C, HDL-C and free fatty acids. Semi-quantitative RT-PCR and Western analysis revealed increased expression of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) in serum and adipose tissue in MSG obese mice. Atorvastatin treatment decreased expression of IL-6, TNF-alpha, nuclear factor kappaB (NF-kappaB) and I-kappa-B (IkappaB) kinase-beta, but increased the expression of IkappaB, in adipose tissue.

CONCLUSION

Atorvastatin is a potential candidate for the prevention and therapy of diseases associated with insulin resistance such as type 2 diabetes mellitus and cardiovascular disease. One possible mechanism underlying the effects of atorvastatin on glucose and lipid metabolism may be to ameliorate a state of chronic inflammation.

Chemerin is a novel adipocyte-derived factor inducing insulin resistance in primary human skeletal muscle cells

OBJECTIVE

Chemerin is an adipokine that affects adipogenesis and glucose homeostasis in adipocytes and increases with BMI in humans. This study was aimed at investigating the regulation of chemerin release and its effects on glucose metabolism in skeletal muscle cells.

RESEARCH DESIGN AND METHODS

Human skeletal muscle cells were treated with chemerin to study insulin signaling, glucose uptake, and activation of stress kinases. The release of chemerin was analyzed from in vitro differentiated human adipocytes and adipose tissue explants from 27 lean and 26 obese patients.

RESULTS

Human adipocytes express chemerin and chemokine-like receptor 1 (CMKLR1) differentiation dependently and secrete chemerin (15 ng/ml from 10(6) cells). This process is slightly but significantly increased by tumor necrosis factor-alpha and markedly inhibited by >80% by peroxisome proliferator-activated receptor-gamma activation. Adipose tissue explants from obese patients are characterized by significantly higher chemerin secretion compared with lean control subjects (21 and 8 ng from 10(7) cells, respectively). Chemerin release is correlated with BMI, waist-to-hip ratio, and adipocyte volume. Furthermore, higher chemerin release is associated with insulin resistance at the level of lipogenesis and insulin-induced antilipolysis in adipocytes. Chemerin induces insulin resistance in human skeletal muscle cells at the level of insulin receptor substrate 1, Akt and glycogen synthase kinase 3 phosphorylation, and glucose uptake. Furthermore, chemerin activates p38 mitogen-activated protein kinase, nuclear factor-kappaB, and extracellular signal-regulated kinase (ERK)-1/2. Inhibition of ERK prevents chemerin-induced insulin resistance, pointing to participation of this pathway in chemerin action.

CONCLUSIONS

Adipocyte-derived secretion of chemerin may be involved in the negative cross talk between adipose tissue and skeletal muscle contributing to the negative relationship between obesity and insulin sensitivity.

Lean, but not obese, fat is enriched for a unique population of regulatory T cells that affect metabolic parameters

Obesity is accompanied by chronic, low-grade inflammation of adipose tissue, which promotes insulin resistance and type-2 diabetes. These findings raise the question of how fat inflammation can escape the powerful armamentarium of cells and molecules normally responsible for guarding against a runaway immune response. CD4(+) Foxp3(+) T regulatory (T(reg)) cells with a unique phenotype were highly enriched in the abdominal fat of normal mice, but their numbers were strikingly and specifically reduced at this site in insulin-resistant models of obesity. Loss-of-function and gain-of-function experiments revealed that these T(reg) cells influenced the inflammatory state of adipose tissue and, thus, insulin resistance. Cytokines differentially synthesized by fat-resident regulatory and conventional T cells directly affected the synthesis of inflammatory mediators and glucose uptake by cultured adipocytes. These observations suggest that harnessing the anti-inflammatory properties of T(reg) cells to inhibit elements of the metabolic syndrome may have therapeutic potential.

Prevalence of metabolic syndrome in Galicia (NW Spain) on four alternative definitions and association with insulin resistance

The present study evaluated the prevalence of the metabolic syndrome (MS) in a representative sample (no.=2860) of adults from the Spanish region of Galicia using the definitions of a) the World Health Organization; b) the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults; c) the European Group for Study of Insulin Resistance; and d) the International Diabetes Federation. In addition, we assess concordance among the different definitions, and the relationships of MS with insulin resistance (IR) as assessed by the homeostatic model assessment (HOMA-IR) index. Our results indicate a high prevalence of MS under all 4 definitions. MS prevalence was higher in men than women on all 4 definitions, and increased significantly with body mass index and age. IR was high among subjects with MS, and the HOMA index was a good discriminator of MS and non-MS on all 4 definitions, suggesting that HOMA index may be a useful predictive tool in clinical practice.

Low cardiorespiratory fitness levels and elevated blood pressure: what is the contribution of visceral adiposity?

Individuals with poor cardiorespiratory fitness have higher blood pressure than fit individuals. Individuals with low fitness levels also tend to be characterized by higher visceral adiposity compared with physically fit individuals. We tested the hypothesis that the relationship between low fitness and elevated blood pressure could be related, at least in part, to the higher level of visceral adipose tissue often found among unfit individuals. This study included 407 asymptomatic, nondiabetic participants. Visceral adipose tissue was assessed by computed tomography, and fitness was measured by a progressive submaximal physical working capacity test. Participants in the highest visceral adipose tissue tertile showed the highest systolic and diastolic blood pressures, whereas participants in the highest fitness tertile had the lowest blood pressure values (P<0.001). When participants were classified into fitness tertiles and then subdivided on the basis of visceral adipose tissue (high versus low), participants with a high visceral adipose tissue had higher systolic and diastolic blood pressure values (P=0.01), independent of their fitness category. Linear regression analyses showed that age and visceral adipose tissue, but not fitness, predicted systolic blood pressure (r(2)=0.11 [P<0.001], 0.12 [P<0.001], and 0.01 [P value nonsignificant], for age, visceral adipose tissue, and fitness, respectively) and diastolic blood pressure (r(2)=0.17 [P<0.001], 0.14 [P<0.001], and 0.01 [P value nonsignificant], for age, visceral adipose tissue, and fitness, respectively). Individuals with high visceral adipose tissue levels have higher blood pressure, independent of their fitness. Visceral adipose tissue may represent an important clinical target in the management of elevated blood pressure.

Body weight, lifestyle, dietary habits and gastroesophageal reflux disease

While lifestyle modifications are currently used as first-line treatment for subjects with gastroesophageal reflux disease (GERD), the pathogenetic role of lifestyle factors and consequently, the efficacy of lifestyle measures is controversial. Our aim was to systematically review the pathogenetic link between overweight/obesity, dietary habits, physical activity and GERD, and the beneficial effect of specific recommended changes, by means of the available literature from the 1999 to the present. Obesity, in particular, abdominal obesity, plays a key role in determining GERD symptoms and complications through mechanical and metabolic effects. Controlled weight loss (by diet or surgery) is effective in improving GERD symptoms. No definitive data exist regarding the role of diet and, in particular, of specific foods or drinks, in influencing GERD clinical manifestations. Moderate physical activity seems to be beneficial for GERD, while vigorous activity may be dangerous in predisposed individuals. In conclusion, being obese/overweight and GERD-specific symptoms and endoscopic features are related, and weight loss significantly improves GERD clinical-endoscopic manifestations. The role of dietary behavior, mainly in terms of specific dietary components, remains controversial. Mild routine physical activity in association with diet modifications, i.e. a diet rich in fiber and low in fat, is advisable in preventing reflux symptoms.

Site-related white adipose tissue lipid-handling response to oleoyl-estrone treatment in overweight male rats

BACKGROUND

Oleoyl-estrone (OE) decreases energy intake while maintaining glucose homeostasis, and energy expenditure at the expense of body fat. White adipose tissue (WAT) depots behave differently under starvation, postprandial state and pharmacologically induced lipolysis.

AIM OF THE STUDY

To understand the mechanism of massive lipid loss from WAT elicited by OE treatment.

METHODS

We used overweight male rats. Rats receiving OE (10 nmol/g) gavages were compared with controls and a pair-fed group. Whole fat pads from the mesenteric, retroperitoneal, epididymal and inguinal subcutaneous sites were excised and analyzed for lipid, DNA, mRNA and the expression of lipogenic, fatty acid transporters and lipase genes.

RESULTS

In OE and pair-fed rats, WAT weights decreased, with the limited loss of cells. Patterns of gene expression in most WAT sites were similar for OE and PF, suggesting a shared mechanism of fat mobilization, but in mesenteric WAT, PF increased lipogenic and fatty acid transporter gene expressions. However, OE inhibited lipogenic expressions more deeply than PF.

CONCLUSIONS

White adipose tissue sites showed different expression patterns, hinting at relatively specialized functions in fat storage; thus, single site analyses cannot be extrapolated to whole WAT. Differences between mesenteric and the other sites suggest that 'visceral fat' should be reserved for this site only, and not applied to other abdominal fat depots (epididymal, retroperitoneal).

Population-wide changes in reported lifestyle are associated with redistribution of adipose tissue

AIMS

The Northern Sweden MONICA project 1986-2004 demonstrated a marked increase in average body mass, an unchanged prevalence of diabetes, and a decrease in myocardial infarctions and lately also in stroke. This study estimates the relative importance of time-trends in lifestyle on average waist and hip circumference on a population level.

METHODS

From a series of independent cross-sectional surveys, a study population of 2,831 men and 2,976 women was formed. Associations between lifestyle factors and waist and hip circumference were estimated. Partial regression coefficients for every level of the lifestyle factors were multiplied by the differences in the proportion of the population reporting the corresponding levels of the respective lifestyle factors in 1986 and 2004. The sum of the product terms for each item represents the respective estimated impact of change in waist and hip circumference.

RESULTS

Lifestyle trends associated with changes in hip circumference were (women/men): higher education level (+4.0 mm/+2.4 mm), fewer smokers (+0.4 mm/+0.9 mm), a slight increase in alcohol consumption (+0.4 mm/+0.3 mm), and more saturated fat from meat in women (-0.9 mm) and more fibre from grains in men (+0.6 mm). Average waist circumference was influenced by increased levels of physical activity (-2.2 mm/-4.6 mm), fewer female smokers (-0.3 mm), and a higher intake of saturated fatty acids from meat among men (+1.8 mm).

CONCLUSIONS

We identified physical activity and the intake of meat and whole-grain products as prime candidates for lifestyle interventions in northern Sweden.

Characterization of a novel obesity phenotype caused by interspecific hybridization

Interspecific hybridization in mammals causes hybrid dysgenesis effects, such as sterility and abnormal placentation. Here, we describe a novel obesity syndrome caused by interspecific hybridization in the genus Mus and show that this obesity, appearing sporadically in F1 littermates derived from inbred strains, has an epigenetic basis. Mus hybrids from various strains of M. musculus and M. spretus were generated and the sporadic obese phenotype was confirmed through assessment of physiological and biochemical parameters in littermates. To understand the underlying mechanisms, large-scale and candidate gene expression assays, global DNA methylation assays and allelic expression analysis were performed. Studies showed that obese hybrids are similar to other known models of obesity. While increased axial growth indicated a defect in POMC pathway, comparison of global gene expression patterns in brain of obese F1 and obese Pomc mutant mice showed little similarity. In F1 obese mice many genes involved in the maintenance of epigenetic states, as well as several imprinted genes, were differentially expressed. Global DNA methylation analysis in brain showed that increased methylation levels were associated with obesity. The imprinted gene Gnasxl, known to be important in lipid homeostasis, was found over expressed in the obese hybrids. Allelic expression and methylation analysis of Gnasxl showed that alterations of epigenetic marks underlying F1 obesity are probably many and multi-factorial.

CONCLUSIONS

This model of obesity, which is both spontaneous and epigenetic, may be a useful tool to address the epigenetic aspects of clinical obesity.

Up-regulated expression of microRNA-143 in association with obesity in adipose tissue of mice fed high-fat diet

MicroRNAs (miRNAs) are short non-coding RNA that post-transcriptionally regulates gene expression. miR-143 has been proposed to play a role in the differentiation of adipocytes in culture. However, the mechanism regulating the expression of miR-143 in adult adipose tissue during the development of obesity in vivo is unknown. Here in, we showed that the expression of miR-143 in the mesenteric fat was up-regulated in mice fed a high-fat diet. Increased miR-143 expression was associated with an elevated body weight and mesenteric fat weight. Furthermore, miR-143 levels were closely correlated with expression levels of adipocyte differentiation markers such as PPARgamma and aP2 as well as plasma levels of leptin, one of the important adipocytokines involved in insulin resistance. These findings provide the first evidence for the up-regulated expression of miR-143 in the mesenteric fat of high-fat diet-induced obese mice, which might contribute to the regulated expression of adipocyte genes involved in the pathophysiology of obesity.

ROC analysis of subcutaneous adipose tissue topography (SAT-Top) in female coronary heart disease patients and healthy controls

The aim of this study was to investigate whether subcutaneous adipose tissue topography (SAT-Top) is different in female CHD patients (n=26) and healthy controls (n=36) matched to age, body size, weight, and BMI. The thicknesses of SAT layers were measured by LIPOMETER at 15 specified body sites. To calculate the power of the different body sites to discriminate between CHD women and healthy controls, receiver operating characteristic (ROC) curve analysis was performed. For each parameter, sensitivity and specificity were calculated at different cutoff points. CHD women showed a significant decrease to 78.36% (p=0.012) at body site 11-front thigh, 73.10% (p=0.012) at 12-lateral thigh, 72.20% (p=0.009) at 13-rear thigh, 66.43% (p<0.001) at 14-inner thigh, and 49.19% (p<0.001) at 15-calf. The best discriminators analysed by ROC curves between female CHD patients and healthy controls turned out to be calf and inner thigh (optimal cut off values: calf: 3.85 mm and inner thigh: 11.15 mm). Stepwise discriminant analysis identified the body sites calf, lateral chest, and inner thigh as significant. In conclusion, information was obtained on the extent to which SAT thickness at each measured body site is able to discriminate between the two subject groups. The good discrimination results obtained for the present dataset are encouraging enough to recommend applying LIPOMETER SAT-Top measurements in further studies to investigate individual risks for CHD.

Novel aspects of adipocyte-induced skeletal muscle insulin resistance

Insulin resistance in skeletal muscle is an early event in the development of diabetes with obesity being one of the major contributing factors. Conditioned medium (CM) from differentiated human adipocytes impairs insulin signalling in human skeletal muscle cells. Recent data on adipocyte-induced insulin resistance in skeletal muscle cells describes underlying mechanisms of this process. Skeletal muscle insulin resistance involves multiple pathways and irreversible changes in the expression level of critical proteins. Furthermore, the reversibility of insulin resistance could be demonstrated. Several strategies to combat insulin resistance have been developed. One recent approach to treat obesity and the metabolic syndrome is the use of endocannabinoid receptor antagonists such as rimonabant. These compounds might also reduce insulin resistance in type 2 diabetes with effects on adipose tissue and liver and possibly skeletal muscle.

Adipose tissue and the metabolic syndrome: focusing on adiponectin and several novel adipokines

The metabolic syndrome represents a cluster of metabolic risk factors that predispose an individual to an increased risk for Type 2 diabetes, cardiovascular diseases and their associated morbidity and mortality. Visceral obesity is thought to be a major culprit. Adipokines secreted from the adipose tissue are now believed to be key factors mediating the metabolic and inflammatory effects of obesity. In this review, we shall examine the evidence suggesting that several novel adipokines, adiponectin, adipocyte fatty acid-binding protein, retinol-binding protein-4 and lipocalin-2, may hold promise as important clinical biomarkers to identify individuals at risk for the metabolic syndrome and related comorbidities.

Endocrine and metabolic effects of fat: cardiovascular implications

The prevalence of obesity is increasing rapidly in both industrialized and developing nations. Obesity causes complex metabolic, endocrine, and hemodynamic changes that may lead to adverse cardiovascular outcomes such as coronary heart disease and congestive heart failure. Adipose tissue is no longer considered to be an inert organ of energy storage, but in fact possesses important endocrine and metabolic functions that are closely involved in energy homeostasis. During the past decade, our understanding of the unique pathophysiologic changes that occur with obesity has rapidly grown. This review discusses our current understanding of the endocrine and metabolic effects of fat and their potential relation to cardiovascular disease.

Distúrbios metabólicos e adiposidade em uma população rural

O objetivo deste estudo transversal foi investigar a prevalência de sobrepeso e adiposidade central (AC) e suas relações com alterações no metabolismo de lipídeos, glicose e níveis pressóricos em uma amostra de 287 indivíduos adultos residentes em uma comunidade rural do Estado de Minas Gerais. Foram realizadas comparações de médias dos indicadores metabólicos: lipoproteínas, glicose e níveis pressóricos, segundo categorias de sobrepeso e AC, usando análise de variância e teste de Tukey. A prevalência de sobrepeso foi de 24,8% (37,4% no sexo feminino; 11,5% no sexo masculino). A AC esteve presente em 28,1% das pessoas (50,3% no sexo feminino; 4,3% no sexo masculino). Indivíduos com AC apresentaram maiores valores médios de pressão arterial (HA), colesterol total, LDL, triglicérides e glicemia de jejum; e menores valores médios de HDL. Foram verificadas associações entre AC e HA, dislipidemia e hiperglicemia. Associações significativas entre sobrepeso e HA, dislipidemia e hiperglicemia também foram evidenciadas. Esses resultados confirmam o potencial efeito das alterações na composição corporal, principalmente em nível central, sobre o metabolismo lipídico e de glicose, e também sobre o aumento dos níveis pressóricos em populações da área rural.

Awareness of Metabolic Concerns in Patients With Bipolar Disorder: A Survey of European Psychiatrists

Purpose.

An online survey of European psychiatrists assessed awareness of the metabolic syndrome and its influence on the management of bipolar disorder.

Materials and methods.

Psychiatrists in the United Kingdom, France, Germany, Spain, and Italy were surveyed from April to June 2006. Eligibility criteria w ere 4–30 years in practice, ≥50% of time in direct patient care, had seen ≥10 bipolar patients in the preceding month. Aggregate data were weighted to represent the practicing physician population per country.

Results.

of 718 respondents, 56% had diagnosed metabolic syndrome. Respondents reported that metabolic syndrome prevalence was higher in bipolar patients (25%) than in the general population (20%). Seventy-two percent felt that metabolic syndrome poses significant health risks, warranting monitoring/treatment, and were most concerned with the bipolar medication adverse effects of weight gain, cognitive impairment, and glucose intolerance. Survey respondents recognized clear differences among psychotropic agents in the propensity to induce metabolic adverse effects. Sixty-five percent of respondents indicated that they had made interviewing and monitoring changes in the past three years as a result of metabolic concerns.

Conclusions.

European psychiatrists view metabolic syndrome as highly prevalent in the general population and in bipolar patients; twothirds have changed their management of bipolar patients because of metabolic health concerns.

Metabolic syndrome in youth: a cross-sectional school-based survey

AIM

To assess the prevalence of metabolic syndrome (MetS) among students attending vocational secondary school (VSE). VSE provides practice-oriented education in which young people learn a specific occupation. Previously we reported VSE to be the type of education with the highest prevalence of overweight and obesity.

METHODS

All data were collected in a cross-sectional school-based survey. Subjects were recruited from a community sample of 869 adolescents in 14 secondary schools. In this total sample all components of the metabolic syndrome were assessed in a subgroup of 506 students. MetS was defined analogous to National Cholesterol Education Program: Adult Treatment Panel III criteria, with modifications for students under 19 years of age.

RESULTS

In the subsample (n=506) 4.1% of the students had metabolic syndrome. There was a significant difference in the prevalence of metabolic syndrome among BMI categories (p<0.001). The prevalence of metabolic syndrome was higher in obese students (39.1%) than in overweight students (2.8%) and normal weight students (0.3%).

CONCLUSION

Being overweight or obese substantially increases the risk for metabolic syndrome, even in an adolescent school population.

Relationship between hyperuricemia and metabolic syndrome

OBJECTIVE

To investigate the relationship between metabolic syndrome and hyperuricemia.

METHODS

A total of 2 374 subjects who received health examination in our hospital from Jan. 2004 to Dec. 2006 were enrolled in our study. Hyperuricemia is defined as >or=7 mg/dl (in men) or >or=6.0 mg/dl (in women). Metabolic syndrome was defined using AHA/NHLBI (American Heart Association/National Heart, Lung, and Blood Institute) criteria.

RESULTS

(1) The overall prevalence of hyperuricemia was 13.10%. The condition was more common in men than in women (19.07% vs 3.42%). (2) Among men, uric acid concentration is statistically significantly positively correlated with waist circumference, blood pressure, and triglyceride. Uric acid is negatively correlated with serum high-density lipoprotein-cholesterol (HDL-C). Uric acid concentration is most strongly correlated with serum triglyceride (r=0.379) and waist circumference (r=0.297). Among women, statistically significant positive correlations were noted for the serum uric acid concentrations with waist circumference, triglyceride and fasting plasma glucose. Serum triglyceride (r=0.329) and waist circumference (r=0.234) are most strongly correlated with uric acid concentrations. (3) Men with hyperuricemia had a 1.634-fold increased risk of metabolic syndrome as compared with those without hyperuricemia [odds ratio (OR)=1.634, P=0.000]. Women with hyperuricemia had a 1.626-fold increased risk of metabolic syndrome (OR=1.626, P=0.000) as compared with those without hyperuricemia.

CONCLUSION

Hyperuricemia is prevalent among Chinese population. Additionally, serum uric acid is positively associated with metabolic syndrome.

Visceral fat and insulin resistance as predictors of non-alcoholic steatohepatitis

AIM

To examine whether visceral fat is associated with non-alcoholic steatohepatitis (NASH), to assess for parameters associated with visceral adiposity and to investigate for factors associated with fibrotic severity in NASH.

METHODS

Thirty NASH and 30 control subjects underwent biochemical tests, anthropometric assessment, bioelectrical impedance, dual energy X-ray absorptiometry and abdominal fat study by CT scan. Liver biopsies were graded according to the Brunt criteria.

RESULTS

NASH subjects had elevated blood pressure, body mass index, waist circumference and waist-to-hip ratio. A greater number of diabetes mellitus, impaired glucose tolerance test and HOMA-IR > 3.5 were found in NASH patients. HOMA-IR > 2.8 (OR 20.98, 95% CI 3.22-136.62; P < 0.001) and visceral fat area > 158 cm(2) (OR 18.55, 95% CI 1.60-214.67; P = 0.019) were independent predictors for NASH. Advanced stage of NASH was found in 15 (50%) patients. HOMA-IR > 3.5 (OR 23.12, 95% CI 2.00-266.23; P = 0.012) and grading of portal inflammation (OR 7.15, 95% CI 1.63-31.20; P = 0.009) were determined as independent risk factors for advanced stage of NASH.

CONCLUSION

Obesity (especially central obesity) and metabolic syndrome are common in Thai NASH. Insulin resistance and elevated visceral fat are risk factors for the presence of NASH. The advanced stage of the disease is related to insulin resistance.

Estimation of truncal adiposity using waist circumference or the sum of trunk skinfolds: a pilot study for insulin resistance screening in hirsute patients with or without polycystic ovary syndrome

Insulin resistance (IR) is an independent risk factor for cardiovascular disease and is a prevalent metabolic disturbance among women with polycystic ovary syndrome (PCOS). Central adiposity, a marker of IR and an accurate anthropometric method to estimate truncal adiposity, may represent a key clinical tool for IR screening in subpopulations at higher metabolic and cardiovascular risk, such as women with PCOS. The aims of the present study were (1) to investigate the influence of androgens on IR and central obesity in overweight or obese hirsute women with or without PCOS and (2) to test the reliability of the sum of trunk skinfolds (subscapular, suprailiac, and abdominal) to estimate truncal adiposity. This observational, cross-sectional study included 37 hirsute patients with body mass index of 25 kg/m(2) or greater and aged between 14 and 41 years. Twenty-four had PCOS, and 13 had ovulatory cycles, normal androgen levels, and isolated hirsutism, named idiopathic hirsutism (IH). Nutritional, anthropometric, clinical, and laboratory evaluations were performed. Body composition was assessed by measurement of waist circumference and skinfold thickness and by dual-energy x-ray absorptiometry (DXA). Both groups presented similar ages, body mass index, and hirsutism score. The PCOS group had higher androgen levels, homeostasis model assessment (HOMA) index, and fasting insulin levels. Free androgen index was positively associated with HOMA, independent of truncal adiposity (r = 0.441, P = .009). Strong correlations were also observed between truncal adiposity measured by DXA and both the sum of trunk skinfolds (r = 0.863, P = .0001) and waist circumference in hirsute patients (r = 0.947, P = .0001). In our study, IR (HOMA index >/=3.8) was associated with truncal obesity, with a more androgenic profile, and with an unfavorable lipid profile. In conclusion, hirsutism per se appears not to be a risk for IR and related cardiovascular disease unless there is presence of central adiposity and/or abnormal androgen profile as observed in patients with PCOS. Waist circumference and the sum of trunk skinfolds represent accurate methods to estimate truncal adiposity, but waist circumference measurement seems to be the simplest method of clinical screening for IR in hirsute women.

Alcohol intake, insulin resistance, and abdominal obesity in elderly men

OBJECTIVE

Moderate and high alcohol intake have been associated with decreased and increased risk of type 2 diabetes, respectively. Insulin resistance, insulin secretion, and abdominal obesity are major predictors of diabetes, but the links with alcohol intake remain contradictory because of limited data.

RESEARCH METHODS AND PROCEDURES

In a population-based cohort of 807 men (age, 70 years), we studied whether alcohol intake was related to insulin sensitivity, measured with the gold standard technique (euglycemic clamp), insulin secretion (early insulin response), or adiposity [BMI, waist circumference (WC), waist-to-hip ratio]. Alcohol intake was self-reported (questionnaire) and was assessed from a validated 7-day dietary record. The cross-sectional associations were evaluated using multivariable linear regression, adjusting for smoking, education level, physical activity, dietary total energy intake, hypertension, diabetes, triglycerides, and cholesterol.

RESULTS

In multivariable models, self-estimated alcohol intake was not related to insulin sensitivity, early insulin response, or BMI, but was positively related to WC (beta-coefficient, 0.77; 95% confidence interval, 0.15 to 1.39; p=0.02) and waist-to-hip ratio (0.006 [0.002-0.009], p=0.003). The association with WC and waist-to-hip ratio was most pronounced in men in the lowest tertile of BMI. The results using dietary records were similar.

DISCUSSION

Evaluated in a large sample in elderly men, neither insulin sensitivity measured by clamp technique nor insulin secretion was significantly associated with alcohol intake. However, high alcohol intake was associated with abdominal obesity, which might explain the higher diabetes risk previously observed in high alcohol consumers.

The relationship between metabolic status and levels of adiponectin and ghrelin in lean women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is commonly associated with insulin resistance, obesity, dyslipidemia and hypertension. Adiponectin, an adipocyte-specific protein with important roles in glucose and lipid homeostasis, possesses antidiabetic and insulin-sensitizing properties. Ghrelin, a protein ligand for the growth hormone secretagog receptor, has been shown to stimulate food intake and to influence energy balance, insulin signaling and glucose metabolism. We aimed to evaluate the relationships between metabolic alterations and adiponectin and ghrelin levels in lean PCOS women, compared with lean and obese women. The study was carried out on 20 non-obese PCOS women aged 20 - 48 years and age-matched groups of 45 healthy lean and 37 obese women. Hormonal and biochemical parameters, adiponectin and ghrelin concentrations and anthropometric data were determined. In PCOS subjects, we found increased homeostasis model assessment - insulin resistance index (HOMA-IR) with non-significant differences in adiponectin and ghrelin concentrations compared with healthy women, although the PCOS group showed a tendency to lower adiponectin levels. However, ghrelin levels in PCOS women were significantly higher than in obese women. Moreover, we observed a negative correlation between adiponectin and testosterone, cholesterol, triglycerides, glucose and diastolic blood pressure in PCOS. In conclusion, it can be suggested that higher values of HOMA-IR with lower adiponectin levels may indicate future development of metabolic syndrome or other metabolic disturbances in lean PCOS women.

Obesity, metabolic syndrome and sleep apnoea: all pro-inflammatory states

Obesity is associated with significant morbidity and mortality and is increasing in prevalence worldwide. Associated conditions include insulin resistance (IR), diabetes, hypertension and dyslipidaemia; a clustering of these has recently been termed as metabolic syndrome. Weight gain is a major predictor of the metabolic syndrome with waist circumference being a more sensitive indicator than body mass index as it reflects both abdominal subcutaneous adipose tissue and visceral adipose tissue (VAT). VAT has more metabolic activity and secretes a number of hormones and pro-inflammatory cytokines which are linked with the metabolic abnormalities listed above. Central obesity also increases the risk of obstructive sleep apnoea syndrome (OSAS), where the sleep disordered breathing may also independently lead to/or exacerbate IR, diabetes and cardiovascular risk. The contribution of OSAS to the metabolic syndrome has been under-recognized. The putative mechanisms by which OSAS causes or exacerbates these other abnormalities are discussed. We propose that activation of nuclear factor kappa B by stress hypoxia and/or by increased adipokines and free fatty acids released by excess adipose tissue is the final common inflammatory pathway linking obesity, OSAS and the metabolic syndrome both individually and, in many cases, synergistically.

Adiponectin gene expression and adipocyte NF-kappaB transcriptional activity in elderly overweight and obese women: inter-relationships with fat distribution, hs-CRP, leptin and insulin resistance

OBJECTIVE

The regulatory processes that modulate adiponectin production and the mechanisms involved in nuclear factor kB (NF-kB) transcriptional activity in human adipocytes are not yet fully known. The aim of our study was to evaluate the inter-relationships between body fat, fat distribution, systemic inflammation, insulin resistance, leptin and the serum and subcutaneous adipose tissue gene expression levels of tumor necrosis factor-alpha (TNF-alpha), adiponectin and the inhibitor kappa B-alpha (IkB-alpha), in subjects with a wide range of body mass index (BMI). We also wanted to determine which of these variables was most closely related to adiponectin gene expression and adipocyte NF-kB transcriptional power.

METHODS

A total of 27 women aged between 50 and 80 years, with BMI ranging from 22.1 to 53.3 kg/m(2), were studied. In all subjects BMI, waist circumference, body composition by dual X-ray absorptometry, triglycerides, cholesterol, high-density lipoprotein cholesterol (HDL-Ch), glucose, insulin, homeostasis model assessment of insulin resistance (HOMA), high-sensitive C-reactive protein (hs-CRP), serum adiponectin, leptin and TNF-alpha were evaluated. Subcutaneous adipose tissue biopsies were taken from the abdomen of all subjects and the mRNA levels of adiponectin, TNF-alpha and IkB-alpha were determined.

RESULTS

BMI and waist circumference were associated positively with leptin, HOMA, and hs-CRP, and negatively with HDL-Ch; waist was also associated with adiponectin and IkB-alpha mRNA. HOMA was negatively associated with serum adiponectin and adiponectin mRNA. Hs-CRP was negatively associated with IkB-alpha mRNA, and was positively associated with HOMA. Step-down multiple regression analysis was performed to determine the joint effects of BMI, waist circumference, triglycerides, HDL-Ch, HOMA, hs-CRP, leptin, serum and TNF-alpha mRNA on adiponectin gene expression: waist circumference and leptin were both included in the best fitting regression equation for predicting adiponectin gene expression (R(2)=0.403, P=0.006). Stepwise multiple regression analysis was performed, considering IkB-alpha mRNA as a dependent variable and BMI, waist, HDL-Ch, HOMA, hs-CRP and adiponectin mRNA as independent variables. Adiponectin mRNA was the only variable to enter the regression (R(2)=0.406, P<0.001).

CONCLUSION

Our results suggest that abdominal adiposity and leptin are independent predictors of adiponectin gene expression and that in human adipocytes, adiponectin gene expression is strongly related to IkB-alpha mRNA.

Diet, obesity and diabetes: a current update

The prevalence of obesity has been increasing at a rapid rate over the last few decades. Although the primary defect can be attributed to an imbalance of energy intake over energy expenditure, the regulation of energy balance is now recognized to be complex. Adipose-tissue factors play a central role in the control of energy balance and whole-body fuel homoeostasis. The regulation of adipose-tissue function, in particular its secretion of adipokines, is impaired by increases in adipose mass associated with obesity, and with the development of insulin resistance and Type 2 diabetes. This review analyses adipose-regulated energy input and expenditure, together with the impact of dietary macronutrient composition on energy balance in relation to susceptibility to the development of obesity and Type 2 diabetes, and how these metabolic conditions may be exacerbated by the consequences of abnormal adipose function. By gaining a greater understanding of how energy balance is controlled in normal, and in obese and diabetic states, a more practical approach can be employed to prevent and better treat obesity and metabolic disorders.

Comparison of different definitions of the metabolic syndrome

BACKGROUND

The International Diabetes Federation (IDF) published a new definition of the metabolic syndrome (MetS). For this definition we compared frequency, concordance, clinical and laboratory stigmata and carotid atherosclerosis with those of the established definitions by the National Cholesterol Education Program (NCEP) and World Health Organization (WHO).

MATERIALS AND METHODS

A total of 1518 subjects (943 men, 575 women) from the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR), free of clinical atherosclerosis, were included in this study. To estimate insulin sensitivity two methods, i.e. homeostasis model assessment of insulin resistance (HOMA-IR) and the short insulin tolerance test, were employed. Carotid intima media thickness (IMT) and plaque extent were quantified for all subjects using high-resolution ultrasound.

RESULTS

Prevalence of the MetS was 18.7% for men and 16.2% for women for the WHO definition, 18.9% and 17.0%, respectively, for the NCEP definition, and 25.8% and 19.5%, respectively, for the IDF definition. Concordance was lower between the definitions of WHO and IDF (< 50%) than between NCEP and IDF (> 67%). Compared to subjects identified by NCEP definition, subjects identified in excess by IDF (3.1-11.7%) showed less insulin resistance and lower IMT and plaque extent indistinguishable from MetS-free subjects.

CONCLUSIONS

Our data suggest that the IDF definition includes subjects as MetS sufferers above these detected by NCEP or WHO, who exhibit considerably less insulin resistance and carotid atherosclerosis blurring the distinction between health and disease.

Uncomplicated metabolic syndrome is associated with prolonged electrocardiographic QTc interval and QTc dispersion

AIM

Metabolic syndrome is associated with increased risk of mortality and morbidity. The present study evaluates the repolarization abnormalities in patients with uncomplicated metabolic syndrome measuring corrected QT interval (QTc) and corrected QT dispersion (QTd) on electrocardiogram.

METHODS

The study involved 83 subjects. A total of 50 individuals met criteria of metabolic syndrome (Group A: 11 men, 39 women, mean body mass index (BMI) 36.7 kg/m2, mean waist circumference 117.3 cm). And 33 participants were healthy normal volunteers (Group B: 9 men, 24 women, mean BMI 21.3 kg/m2, mean waist circumference 76.2 cm). The two groups were matched for age and sex. Metabolic syndrome was diagnosed according to the Adult Treatment Panel III criteria. The QTc intervals and QTd were measured.

RESULTS

Patients with uncomplicated metabolic syndrome had significantly higher values of QTc-min, QTc-max, and QTd than control group (P < 0.001).

CONCLUSION

Patients with uncomplicated metabolic syndrome have a greater dispersion of ventricular repolarization time and increased QTc-min and QTc-max.

Maternal taurine supplementation in the late pregnant rat stimulates postnatal growth and induces obesity and insulin resistance in adult offspring

An adequate supply of taurine during fetal life is important for normal beta-cell development and insulin action. An altered availability of taurine may programme glucose metabolism in utero and result in type 2 diabetes in adult age. We examined whether maternal taurine supplementation in late pregnant rats affects postnatal growth, adult body composition, insulin sensitivity and endogenous insulin secretion in intrauterine growth restricted (IUGR) and normal offspring. Uterine artery ligation or sham operations were performed on gestational day (GD) 19. Taurine supplementation was given to half of the dams from GD 18 until term, resulting in four groups of offspring: sham (n = 22), sham/taurine (n = 22), IUGR (n = 22) and IUGR/taurine (n = 24). The offspring were studied at 12 weeks of age. In offspring with normal birth weight, fetal taurine supplementation markedly stimulated postnatal growth. In sham/taurine females, fat depots, plasma free fatty acid and leptin concentrations were increased, and insulin sensitivity was reduced. Insulin sensitivity was unaltered in IUGR and IUGR/taurine offspring. However, whereas IUGR offspring showed little catch-up growth, 50% of IUGR/taurine animals displayed complete catch-up at 12 weeks of age, and these animals had increased fat depots and reduced insulin sensitivity. In conclusion, taurine supplementation in late gestation resulted in accelerated postnatal growth, which was associated with adult obesity and insulin resistance in both IUGR and normal offspring. This effect was particularly evident in females. These data suggest that fetal taurine availability is an important determinant for postnatal growth, insulin sensitivity and fat accumulation.

Features of metabolic syndrome in non-diabetic Italians and Brazilians: a discriminant analysis

This aim of this study was to compare the characteristics of metabolic syndrome (MetS) in a Brazilian and an Italian population. The subjects were non-diabetic men and women aged 40-74 years from population-based surveys: 1242 from Brazil and 1198 from Italy. Logistic regression models were used to compare adjusted prevalence rates and make a discrimination analysis to distinguish the subjects with a diagnosis of MetS in the two groups. Dyslipidemia [low high-density lipoprotein (HDL)-cholesterol] and impaired fasting glucose were more prevalent among the Brazilians, and increased blood pressure and abdominal obesity (in men) among the Italians. Generally, the Italians showed higher prevalence of overall obesity and high pulse-pressure, and the Brazilians had higher prevalence of metabolic markers of insulin resistance. Among the subjects with the syndrome, HDL-cholesterol was the most discriminant factor, followed by plasma uric acid levels (which were higher in the Brazilians). The Italian men had a larger waist circumference and the Italian women higher body mass index values than the Brazilians. Italians had higher systolic and lower diastolic pressure values. The patterns of the metabolic alterations seemed to be more linked to insulin resistance among Brazilian subjects, whereas obesity seemed to play a more important role among the Italians. Although they are not sufficient to support the hypothesis of differences in the underlying pathophysiological processes between these groups, our results illustrate the difficulty of using a single unifying definition of MetS, and suggest that different benefits may be obtained from treatments targeting obesity, blood pressure or insulin resistance.

Reported food intake and distribution of body fat: a repeated cross-sectional study

Background

Body mass, as well as distribution of body fat, are predictors of both diabetes and cardiovascular disease. In Northern Sweden, despite a marked increase in average body mass, prevalence of diabetes was stagnant and myocardial infarctions decreased. A more favourable distribution of body fat is a possible contributing factor.

This study investigates the relative importance of individual food items for time trends in waist circumference (WC) and hip circumference (HC) on a population level.

Methods

Independent cross-sectional surveys conducted in 1986, 1990, 1994 and 1999 in the two northernmost counties of Sweden with a common population of 250000. Randomly selected age stratified samples, altogether 2982 men and 3087 women aged 25–64 years. Questionnaires were completed and anthropometric measurements taken. For each food item, associations between frequency of consumption and waist and hip circumferences were estimated. Partial regression coefficients for every level of reported intake were multiplied with differences in proportion of the population reporting the corresponding levels of intake in 1986 and 1999. The sum of these product terms for every food item was the respective estimated impact on mean circumference.

Results

Time trends in reported food consumption associated with the more favourable gynoid distribution of adipose tissue were increased use of vegetable oil, pasta and 1.5% fat milk. Trends associated with abdominal obesity were increased consumption of beer in men and higher intake of hamburgers and French fried potatoes in women.

Conclusion

Food trends as markers of time trends in body fat distribution have been identified. The method is a complement to conventional approaches to establish associations between food intake and disease risk on a population level.

Body composition, dietary intake, and energy expenditure after laparoscopic Roux-en-Y gastric bypass and laparoscopic vertical banded gastroplasty: a randomized clinical trial

OBJECTIVE

To assess body composition, eating pattern, and basal metabolic rate in patients undergoing obesity surgery in a randomized trial.

INTRODUCTION

There is limited knowledge regarding how different bariatric surgical techniques function in terms of altering body composition, dietary intake, and basic metabolic rate.

METHODS

Non-superobese patients were randomized to laparoscopic Roux-en-Y gastric bypass (LGBP, n = 37) or laparoscopic vertical banded gastroplasty (LVBG, n = 46). Anthropometry, dual-energy x-ray absorptiometry (DEXA), computed tomography (CT), indirect calorimetry, and reported dietary intake were registered prior to and 1 year after surgery.

RESULTS

Follow-up rate was 97.6%. LGBP patients had significantly greater reduction of waist circumference and sagittal diameter compared with LVBG. DEXA demonstrated a larger reduction of body fat in all compartments after LGBP, especially at the trunk (P<0.001). CT demonstrated more reduction of the visceral fat (P=0.016). Patients were able to eat all types of food after LGBP, although about 30% claimed they avoided fats. LGBP patients decreased their proportion of dietary fat significantly more than those operated on with LVBG (P = 0.005), who consumed more sweet foods and avoided whole meat and vegetables. Lean tissue mass (LTM) was proportionally less reduced, especially in men, after LGBP. The decreases in BMR postoperatively reflected the lower body mass in a pattern that did not differ among the groups.

CONCLUSION

LGBP patients demonstrated better outcomes compared with LVBG patients in terms of body composition. Energy expenditure developed as expected postoperatively. A "steering" away from fatty foods after LGBP may be an important mechanism of action in gastric bypass.

The altered fluid distribution in obesity may reflect plasma hypertonicity

OBJECTIVE

This study explored whether the increased extracellular relative to intracellular fluid (ECF/ICF) ratio in obesity might reflect osmotic effects of elevated plasma solute concentrations.

DESIGN

Cross-sectional, epidemiological survey.

SETTING AND SUBJECTS

The present analysis used nationally representative data from the Third National Health and Nutrition Examination Survey on community-dwelling adults (aged 40-59 years) in the US without evidence of glucose dysregulation or chronic disease (n=1285).

INTERVENTION

Body mass index (BMI) was estimated from measured height and weight. Total body reactance, an index of body fluid distribution, was determined by bioelectrical impedance analysis. Plasma tonicity (the cumulative index of osmotically effective plasma solute) was estimated from plasma glucose, sodium and potassium. Sex-specific relative odds of lower reactance (<or=50 Omega/m for women, <or=40 Omega/m for men) and plasma hypertonicity (tonicity >or=295 mmol/l) associated with overweight (25<or=BMI <30) and obesity (BMI>or=30) were estimated using logistic regression models that controlled for sociodemographic variables, smoking, leisure-time physical activity, total energy intake, serum creatinine, plasma insulin and glucose. Multinomial logistic regression models tested for associations between weight status and specific serum solute.

RESULTS

Independent of covariates, in men and women, overweight and obesity were associated with increased odds of lower reactance and hypertonicity. Overweight and obese individuals with lower reactance had significantly higher serum sodium than normal weight individuals.

CONCLUSIONS

Elevated plasma solute concentrations are associated with obesity in free-living adults. Physicians and researchers should be alert to a possible link between hypertonicity and obesity.

SPONSORSHIP

Grants from the NIH, Nestle Waters.

Metabolic syndrome by the international diabetes federation definition in Hong Kong Chinese

In this report, we aimed to examine the impact of the new International Diabetes Federation (IDF) definition on the prevalence and clinical characteristics of subjects with metabolic syndrome (MES). Data were obtained from a prevalence survey for cardiovascular risk factors in a Hong Kong Chinese working population. There were 1513 subjects well representing all occupational groups from managers to general laborers [910 (60.1%) men and 603 (39.9%) women (mean age 37.5+/-9.2, median 37.0, range 18-66 years)]. The crude prevalence of MES defined by the IDF criterion was 7.4% (compared to other criteria: NCEP, 9.6%; WHO, 13.4% and EGIR, 8.9%). The age-standardized prevalence of MES by the IDF criterion was 8.8% in women and 7.3% in men. Subjects with MES defined by IDF criterion had higher body mass index and waist compared to those with MES defined by NCEP or WHO criteria, and lower triglyceride compared to those with MES defined by NCEP criterion after adjustment for age, gender and smoking. Non-MES subjects defined by IDF criterion had higher 2h glucose and insulin resistance compared to non-MES subjects defined by WHO. In conclusion, the new IDF criterion for MES is easy to implement in clinical practice. It may be potentially more 'specific' in identifying subjects with MES although compared to the NCEP criterion, it may have missed a proportion of subjects, especially men, who have metabolic derangement. Prospective and interventional studies are needed to validate the prognostic values of this new definition in comparison with other existing definitions.

Chronic administration of olanzapine induces metabolic and food intake alterations: a mouse model of the atypical antipsychotic-associated adverse effects

RATIONALE

Most of atypical antipsychotics (AAPs) are highly related to a major risk of metabolic drawbacks leading to dyslipidemia and obesity.

OBJECTIVE

To set up a mouse model of the AAP-associated weight gain in mice under the influence of chronic olanzapine regimen.

MATERIALS AND METHODS

Female mice were housed in pairs and habituated to spontaneous feeding with a high-palatable diet (10% sucrose wet mash). Firstly, we orally administered olanzapine (0.75, 1.5 and 3 mg/kg), evaluating body weight and periuterine fat mass, as well as insulin, non-esterified fatty acids, triglycerides, and glucose levels. In a second experiment, we assessed the effect of olanzapine on energy expenditure through indirect calorimetry (IC). A third experiment was conducted to investigate the effects of olanzapine on a high fat-high sweet palatable diet (10% sucrose + 30% fat, HF-HS) in mice implanted with subcutaneous osmotic mini-pumps. Locomotor activity was also assessed.

RESULTS

In experiment 1, the highest dose of chronically administered olanzapine (3 mg/kg) induced significant weight gain accompanied by augmentation of periuterine fat depots, with no changes in locomotor activity. In experiment 2, chronic administration did not alter energy expenditure, whereas, decreased respiratory quotient (RQ). In experiment 3, subcutaneously infused olanzapine evidenced a dose and time-dependent increase of body weight and HF-HS diet consumed. Notably, serum analyses revealed a hyperinsulinemia together with increased levels of triglycerides and glucose.

CONCLUSIONS

In this study, we describe in female mice metabolic alterations matching the metabolic syndrome, thus resembling the clinical situation of schizophrenic patients taking AAPs.

[Comorbidities and complications of adiposis]

Overweight and obesity are associated with a high number of complications and co-morbidities. Obesity can affect almost all tissues and organs of the body. Obesity is associated with the components of the metabolic syndrome and is the leading cause of type 2 diabetes. Either obesity itself or co-morbidities of obesity are responsible for the increased cardiovascular risk. The increased overall mortality risk is due to cardiovascular and other complications like the higher prevalence and incidence of malignant tumors. Other complications of obesity like the polycystic ovary syndrome or the obstructive sleep apnea syndrome are relatively unknown but important and frequent. Medical care of people with obesity should focus not only on weight loss but also on complications and co-morbidities.

Body cell mass measured by total body potassium in normal-weight and obese men and women

OBJECTIVE

Total body potassium (TBK) concentration is linearly correlated with the size of the body cell mass (BCM). The aim of this study was to compare BCM in normal-weight and obese individuals.

METHODS

271 individuals (207 males, 64 females), 20 to 67 years of age, participated in this study. Subjects were separated by body mass index (BMI): BMI < 25 kg/m(2) (BMI-L) and BMI > 25 kg/m(2) (BMI-H). (40)K was assessed using a whole-body counter and BCM was calculated.

RESULTS

BCM and TBK were significantly greater in men, with a trend to be greater in women in BMI-H compared to men in BMI-L. TBK/body weight was significantly lower, while TBK/height was significantly greater for men and women in BMI-H compared to men and women in BMI-L. Fat-free mass (FFM) was significantly greater for men in BMI-H, with no significant differences in FFM between the two groups of women.

CONCLUSIONS

The healthy obese subjects in the present study had a greater BCM than the non-obese subjects. These results indicate that it is important to assess BCM in obese individuals because it could influence the type of weight loss regimen that will be used in order to preserve BCM.

Pathways leading to muscle insulin resistance--the muscle--fat connection

Type 2 diabetes is a heterogeneous disease characterized by hyperglycemia and insulin resistance in peripheral tissues such as adipose tissue and skeletal muscle. This review focuses on obesity as one of the major environmental factors contributing to the development of diabetes. It has become evident that adipose tissue represents an active secretory organ capable of releasing a variety of cytokines such as TNFalpha, IL-6, adiponectin and other still unknown factors that might constitute the missing link between adipose tissue and insulin resistance. In fact, adipocyte-derived factors are significantly increased in obesity and represent good predictors of the development of type 2 diabetes. The negative crosstalk between adipocytes and skeletal muscle cells leads to disturbances in muscle cell insulin signalling and insulin resistance involving major pathways in inflammation, cellular stress and mitogenesis. Positive regulators of insulin sensitivity include the adipocyte hormone adiponectin and inhibitors of inflammatory pathways such as JNK-, IKK- and ERK-inhibitors. In summary, a better knowledge of intracellular and intercellular mechanisms by which adipose tissue affects skeletal muscle cell physiology may help to develop new strategies for diabetes treatment.

Free fatty acids are associated with obesity, insulin resistance, and atherosclerosis in renal transplant recipients

BACKGROUND

Insulin resistance (IR) may be implicated in the pathogenesis of atherosclerosis in renal transplant recipients (RTRs) and be contributed to, in part, by free fatty acids (FFAs), produced in excess in centrally obese individuals. The aim of this study was to determine the prevalence of IR and the relationships between FFAs, central obesity, and atherosclerosis in a cohort of prevalent RTRs.

METHODS

Observational data were collected on 85 RTRs (mean age 54 years; 49% male, 87% Caucasian). Fasting serum was analyzed for FFAs, glucose, and insulin; IR was calculated using the homeostasis model assessment (HOMA-IR) score. Vascular structure was assessed by carotid intima-media thickness (IMT) measurement. Linear regression analyses were performed to determine the factors associated with IR and atherosclerosis.

RESULTS

IR occurred in 75% of RTRs, and FFA levels were independently associated with its occurrence (beta: -0.55, 95% CI: -1.02 to -0.07, P = 0.02). Other variables independently associated with IR were male sex, body mass index, central obesity, diabetes, systolic blood pressure and corticosteroid use. There was a significant correlation between FFA levels and IMT (r = 0.3, P=0.01). On multivariate analysis, IMT correlated with elevated FFA (beta: 0.07, 95% CI: 0.02-0.12, P = 0.007), diabetes mellitus (P = 0.05), older age (P < 0.002), and a body mass index >25 kg/m (P = 0.002).

CONCLUSIONS

FFAs are associated with the development of IR and may be involved in the pathogenesis of atherosclerosis in RTRs. Additional studies are required to explore these associations further before considering whether an interventional trial aimed at lowering FFA would be a worthwhile undertaking.